Apparatus and method for transmitting and receiving beam information in wireless communication system

ABSTRACT

The present disclosure relates to transmitting and receiving beam information in a wireless communication system. An operation of a receiving end includes: generating a signal indicating two or more analogue transmission beams which are allocable to the receiving end; and transmitting the signal. In addition, the present disclosure includes other embodiments different from the embodiment described above.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/025,532,filed Mar. 28, 2016, which is the 371 National Stage of InternationalApplication No. PCT/KR2014/008923, filed Sep. 25, 2014, which claimspriority to Korean Application No. 10-2013-0115280, filed Sep. 27, 2013,the disclosures of which are incorporated herein by reference into thepresent disclosure as if fully set forth herein.

BACKGROUND 1. Field

Exemplary embodiments of the present disclosure relate to transmittingand receiving beam-related information in a wireless communicationsystem.

2. Description of the Related Art

Wireless communication systems are developing to support a higher datatransfer rate to satisfy an increasing demand for wireless data traffic.The 4^(th) Generation (4G) system which is commonly used in recent yearshas been developed with the aim of enhancing spectral efficiency toincrease the data transfer rate. However, the enhancement in thespectral efficiency is not expected to satisfy the increasing demand forwireless data traffic.

As a solution for providing a higher data transfer rate, use of abroader frequency band may be considered. The present mobilecommunication cellular system uses a bandwidth of about 5 GHz. However,since the frequency is a finite resource, it is difficult to guaranteethe broader frequency band. Therefore, there is a need for a method forguaranteeing a wideband frequency at a higher frequency rather than acurrently used band.

As the frequency for wireless communication increases, a propagationpath loss increases. Due to the propagation path loss, a propagationdistance is relatively shortened and thus a service coverage is reduced.As one of the important techniques for solving these problems, that is,reducing the propagation path loss and increasing the propagationdistance, beamforming is being in the spotlight.

Beamforming for transmission, which is performed for transmissionsignals, normally uses a plurality of antennas to focus signalstransmitted from the antennas in a specific direction. A set of aplurality of antennas may be referred to as an array antenna, and eachof the antennas included in the array antenna may be referred to as anantenna element. The beamforming for transmission can increase apropagation distance of signals and also rarely transmits signals inother directions, so that interference on other users can be greatlyreduced. A receiving side may perform beamforming for reception withrespect to reception signals using a reception array antenna. Thebeamforming for reception increases sensitivity of reception signalsentering in a corresponding direction by focusing reception of waves ina specific direction, and blocks interference signals by excludingsignals received in directions other than the corresponding direction.

In addition, as a transmission frequency increases, a wavelength ofwaves decreases. Therefore, when a half-wave antenna is provided, thearray antenna can be configured by more antenna elements in the samearea. That is, when a high frequency band is used, a higher antenna gaincan be obtained than when beamfoming is applied in a low frequency band.

SUMMARY

To address the above-discussed deficiencies, it is a primary object toprovide an apparatus and method for efficiently scheduling in a wirelesscommunication system based superhigh frequency beamforming.

Another object of the present disclosure is to provide an apparatus andmethod for managing efficient scheduling in a wireless communicationsystem when different wireless environment coexist.

Another object of the present disclosure is to provide an apparatus andmethod for uplink signaling and scheduling in a wireless communicationsystem.

Another object of the present disclosure is to provide an apparatus andmethod for indicating two or more allocable analogue transmission beamsin a wireless communication system.

Another object of the present disclosure is to provide an apparatus andmethod for allocating an analogue transmission beam other than a bestanalogue transmission beam in a wireless communication system.

According to an aspect of the present disclosure, an operation method ofa receiving end in a wireless communication system includes: generatinga signal indicating two or more analogue transmission beams which areallocable to the receiving end; and transmitting the signal.

According to another aspect of the present disclosure, an operationmethod of a transmitting end in a wireless communication systemincludes: receiving a signal indicating two or more analoguetransmission beams which are allocable to a receiving end; andallocating an analogue transmission beam to the receiving end based onthe signal.

According to another aspect of the present disclosure, a receiving endin a wireless communication system includes: a controller for generatinga signal indicating two or more analogue transmission beams which areallocable to the receiving end; and a transmission unit for transmittingthe signal.

According to another aspect of the present disclosure, a transmittingend in a wireless communication system includes: a reception unit forreceiving a signal indicating two or more analogue transmission beamswhich are allocable to a receiving end; and a controller allocating ananalogue transmission beam to the receiving end based on the signal.

In a wireless communication system, preferred beam information isacquired in various ways at a receiving end, so that a transmitting endcan obtain a degree of freedom of adaptively allocating a beam to thereceiving end. Accordingly, a load balance between beams as well as thedegree of freedom can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a view showing a scheduling area according to whetherbeamforming is performed or not in a wireless communication systemaccording to an exemplary embodiment of the present disclosure;

FIG. 2 illustrates a view showing examples of different wirelessenvironments in a wireless communication system according to anexemplary embodiment of the present disclosure;

FIG. 3 illustrates a view showing examples of transmission beams andreception beams in a wireless communication system according to anexemplary embodiment of the present disclosure;

FIG. 4 illustrates a view showing a frame structure in a wirelesscommunication system according to an exemplary embodiment of the presentdisclosure;

FIG. 5 illustrates a view showing an example of interpretation of uplinksignaling in a wireless communication system according to an exemplaryembodiment of the present disclosure;

FIG. 6 illustrates a view showing an example of classified beam groupsin a wireless communication system according to an exemplary embodimentof the present disclosure;

FIG. 7 illustrates a view showing an example of a configuration ofbitmap in a wireless communication system according to an exemplaryembodiment of the present disclosure;

FIG. 8 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to an exemplaryembodiment of the present disclosure;

FIG. 9 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to another exemplaryembodiment of the present disclosure;

FIG. 10 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to another exemplaryembodiment of the present disclosure;

FIG. 11 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to another exemplaryembodiment of the present disclosure;

FIG. 12 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to another exemplaryembodiment of the present disclosure;

FIG. 13 illustrates a view showing an operation procedure of atransmitting end in a wireless communication system according to anexemplary embodiment of the present disclosure;

FIG. 14 illustrates a view showing an operation procedure of atransmitting end in a wireless communication system according to anotherexemplary embodiment of the present disclosure;

FIG. 15 illustrates a view showing an operation procedure of atransmitting end in a wireless communication system according to anotherexemplary embodiment of the present disclosure;

FIG. 16 illustrates a view showing an operation procedure of atransmitting end in a wireless communication system according to anotherexemplary embodiment of the present disclosure;

FIG. 17 illustrates a view showing a block configuration of a receivingend in a wireless communication system according to an exemplaryembodiment of the present disclosure;

FIG. 18 illustrates a view showing a block configuration of atransmitting end in a wireless communication system according to anexemplary embodiment of the present disclosure; and

FIG. 19 illustrates a view showing a block configuration for beamformingin a wireless communication system according to an exemplary embodimentof the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings. In the followingdescription, well-known functions or constructions are not described indetail since they would obscure the invention in unnecessary detail.Also, the terms used herein are defined according to the functions ofthe present invention. Thus, the terms may vary depending on user's oroperator's intension and usage. That is, the terms used herein must beunderstood based on the descriptions made herein.

Hereinafter, technology for transmitting and receiving preferred beaminformation in a wireless communication system will be explained. In thefollowing explanation, the term for expressing information foridentifying beams and the term for configuring other preferred beaminformation will be used for convenience of explanation. Therefore, thepresent disclosure is not limited to the terms which will be describedbelow, and other terms indicating objects having the same technicalmeaning may be used.

FIG. 1 illustrates a view showing a scheduling area according to whetherbeamforming is performed or not in a wireless communication systemaccording to an exemplary embodiment of the present disclosure. FIG. 1illustrates a scheduling-allowable area for a terminal 110 using asingle beam when a base station 120 performs beamforming, that is, thebase station 120 transmits signals using directional beams, and ascheduling-allowable area for the terminal 110 when the base station 120does not perform beamforming, that is, the base station 120 transmitssignals using omni-directional beams.

When the beamforming is applied, the base station 120 and the terminal110 should inform each other of their preferred analogue beamdirections. Since the maximum number of beams that the base station 120can transmit simultaneously is normally limited by hardware capability(for example, the number of radio frequency (RF) chains, etc.), theremay be a limitation on user scheduling.

Referring to FIG. 1, when beamforming is not performed, the transmissionsignals of the base station 120 do not have directivity. Accordingly,the base station 120 can perform scheduling wherever the terminal 110 islocated within a cell coverage. In other words, when beamforming is notperformed, the base station 120 may perform user scheduling in alldirections at every unit time.

On the other hand, when beamforming is performed, the transmissionsignals of the base station 120 have directivity corresponding to aselected beam. Accordingly, when the beamforming is performed, the basestation 120 should perform scheduling with respect to users who arelocated in the direction of a limited number of analogue beams at everyunit time. For example, when a single beam is considered, in order forthe base station 120 to be able to perform scheduling with respect tothe terminal 110, the terminal 110 should be located within apredetermined angle range with reference to the direction of the beam orshould be located in an area that a reflected wave of the beam can reachif the direction of the beam is not considered. That is, when thebeamforming is performed, the degree of freedom of scheduling may bereduced. As result, when usable beams are limited due to the number ofconnected terminals or geographical distribution, and the terminal 110is not located in an area corresponding the direction of the usablebeams, it may be difficult to perform scheduling with respect to theterminal 110.

When beamforming is performed for downlink communication, the basestation may determine a best analogue beam for each array antenna, andfurthermore, may determine a digital precoding vector to be applied tosignals to be transmitted through a plurality of array antennas. Forexample, the analogue beam and the precoding vector may be selected bythe terminal and may be fed back to the base station, and then may beused for scheduling in the base station. However, when digitalbeamforming is not performed, the precoding vector may not bedetermined.

The scheduling may be limited according to the number of usable beams ofthe base station and a frequency band. The limitation on the schedulingmay cause problems such as a service delay, which is accompanied bycalculation of scheduling of the base station in a region where thereare many users. In addition, use of a superhigh frequency band may leadto problems that transmissivity of signals becomes lower than at arelatively lower frequency, and thus transmittance from an outdoor spaceto an indoor space is made difficult. Considering the communicationenvironment such as the limitation on scheduling or degradedtransmissivity, use of a repeater may be considered.

FIG. 2 illustrates a view showing examples of different wirelessenvironments in a wireless communication system according to anexemplary embodiment. FIG. 2 illustrates two types of wirelessenvironments. Referring to FIG. 2, a terminal A 211 is located in anoutdoor area and a terminal B 212 is located in an indoor area. Channelmodeling experiments conducted NYU (Prof. Rappaport) revealed thatterminals in an outdoor area can normally communicate in any conditionof Line of Sight (LOS) and Non-LOS (NLOS). Accordingly, the terminal A211 transmits and receives radio signals to and from a base station 220.However, in the indoor area, a repeater 230, a Radio Remote Header(RRH), etc. may be used to overcome the low transmissivity of signalsentering the indoor area as described above. In this case, the terminalB 212 may transmit and receive radio signals to and from the repeater230. Since the repeater 230 is located in the indoor area, the repeater230 does not need to increase a propagation distance throughbeamforming. Accordingly, the repeater 230 may have an omni-directionalradiation property of radiating signals in all directions withoutbeamforming.

That is, the terminals 211 and 212 may be located within a cell whichtransmits omni-directional signals or a cell which transmits directionalsignals according to circumstances. In other words, the terminals 211and 212 may be in a wireless environment in which beamforming isperformed or a wireless environment in which beamforming is notperformed. In addition, when beamforming is performed, the wirelessenvironment may be divided according to a beam width used in atransmitting end. In the case of FIG. 2, the outdoor area is illustratedas a wireless environment in which beamforming is performed and theindoor area is illustrated as a wireless environment in whichbeamforming is not performed. However, the indoor area and the outdoorarea, which are considered in the present disclosure, are not alwaysrelated to whether beamforming is performed or not as shown in FIG. 2.Accordingly, a wireless environment in which beamforming is notperformed may be established in the outdoor area or a wirelessenvironment in which beamforming is performed may be established in theindoor area.

FIG. 3 illustrates a view showing examples of transmission beams andreception beams in a wireless communication system according to anexemplary embodiment of the present disclosure.

Referring to FIG. 3, a base station 320 uses beams #1 to #M_(t) indifferent directions, and a terminal 310 uses beams #1 to #M_(r) indifferent directions. The beams illustrated in FIG. 3 refer to one ofthe transmission beams and the reception beams or both the transmissionbeams and the reception beams. In the case of downlink communication,the base station 320 transmits signals to the terminal 310 using atleast one of the beams #1 to #M_(t). In this case, the base station 320determines beams preferred by the terminal 310.

To achieve this, the base station 320 may transmit training signalsusing beams #1 to #M_(t), and the terminal 310 may measure channelqualities regarding the training signals and select a best transmissionbeam. The channel quality may include at least one of Received SignalStrength (RSS) and channel capacity of reception signals. Herein, thetraining signal may be referred to as a reference signals, a preamble, amidamble, a pilot, etc. Furthermore, when the terminal 310 performsbeamforming for reception, the terminal 310 may receive signals usingthe beams #1 to M_(r) with respect to the respective beams from the basestation 320, measure the channel qualitiesy of the signals, and thenselect a best reception beam. Thereafter, the terminal 310 may informthe base station 320 of its preferred transmission beam or receptionbeam by feeding the selected transmission beam or reception beam back tothe base station 320.

In the case of FIG. 3, the beams of the terminal 310 have sequentialidentifiers (IDs) in the counter clockwise direction, and the beams ofthe base station 320 have sequential IDs in the clockwise direction.However, according to another exemplary embodiment of the presentdisclosure, the IDs of the beams may be allocated in other ways, andfurthermore, may not be sequential in a specific direction.

FIG. 4 illustrates a view showing a frame structure in a wirelesscommunication system according to an exemplary embodiment of the presentdisclosure.

Referring to FIG. 4, the frame includes Ns slots, and is divided intocontrol channels 410 to relay control information to a user, beammeasurement slots 420 to transmit Beam Measurement Reference Signals (BMRSs), and data slots 430 to relay traffic to the user. One slot isformed of as many Orthogonal Frequency Division Multiplexing (OFDM)symbols as N_(symb). A base station performs beamforming with a specificanalogue beam during a single OFDM symbol period in the beam measurementslots 420 to transmit the beam measurement reference signals in thedirection of the analogue beam. A terminal may receive the beammeasurement reference signals through the beam measurement slots 420during a time when combinations of all beams are available, and mayselect a best beam based on measured channel quality information.Herein, the analogue beam may be identified by a beam ID.

As described above, a receiving end selects a preferred beam andtransmits information (for example, a beam ID) indicating the selectedbeam to a transmitting end. In this case, when the transmitting end usesomni-directional beams, in other words, when the transmitting end isplaced in a wireless environment in which beamforming is not performed,a plurality of beams may be selected. In addition, a plurality of beamsmay be selected due to the location of the receiving end, influence ofreflected waves, etc. even when the transmitting end performsbeamforming. For example, when the receiving end is located at thecenter of a cell, there may exist a plurality of beams having a bestchannel quality.

When a plurality of beams have a high channel quality, that is, when thereceiving end selects the plurality of beams, the receiving end maytransmit measurement information on the plurality of beams, so that thedegree of freedom of scheduling can be enhanced in comparison with acase in which a single selected beam is informed. Hereinafter, the‘measurement information on the plurality of beams’ will be referred toas ‘beam measurement information’ for convenience of explanation. Thatis, the beam measurement information indicates that analogue beams canbe arbitrarily allocated. In particular, according to an exemplaryembodiment of the present disclosure, the beam measurement informationindicates two or more allocable analogue beams. The range of thearbitrarily allocable analogue beams may vary according a specificformat of the beam measurement information. For example, the beammeasurement information may be configured from the perspective of theentire beams or individual beams.

Uplink signaling related to a preferred beam according to an exemplaryembodiment of the present disclosure may include an item as shown intable 1 presented below:

TABLE 1 Number of Bits Variable 1 Items Best beam ID SBQI (Similar BeamQuality Indicator)

In table 1, the ‘best beam ID’ is a beam which is selected based onmeasurement using beam measurement reference signals, and indicates abeam having a best channel quality. The ‘SBQI’ is beam measurementinformation indicating channel quality information regarding all of thebeams, and may be formed of 1 bit and indicate whether a beam other thanthe beam having the best channel quality is allowed to be allocated ornot. The number of bits of the ‘best beam ID’ field may vary accordingto the number of analogue beams used in the system. As shown in table 1,the number of bits of the ‘SBQI’ field may be two or more. Although notshown in table 1, the uplink signaling may further include at least oneof a Hybrid Automatic Repeat reQuest (HARQ) ACKnolwedge/Non-ACK(ACK/NACK), a Precoding Matrix Index (PMI), a Rank Indicator (RI), and aChannel Quality Indicator (CQI).

When the ‘SBQI’ is set to a positive value (for example, 1), any beamscan be allocated at the transmitting end, and, when the ‘SBQI’ is set toa negative value (for example, 0), a specific analogue beam is requiredto be allocated. That is, the SBQI which is set to the positive valueinforms that signals can be transmitted to the receiving end with a beamother than the beam indicated by the best beam ID. Herein, allowing theallocation of other beams may mean that the channel qualities of thecorresponding beams guarantee a minimum service quality. Accordingly,the transmitting end may allocate a beam other than the beam indicatedby the best beam ID to the receiving end. In other words, thetransmitting end can acquire the degree of freedom of scheduling for thereceiving end.

In order to determine the value of the ‘SBQI,’ the receiving end maydetermine whether each beam satisfies a predetermined condition or not.When all of the beams satisfy the predetermined condition, the ‘SBQI’ isset to a positive value. In this case, the receiving end determines withreference to the transmission beams. The reception beams are notrequired to be allocated to the transmitting end, and may be arbitrarilyselected by the receiving end. That is, the receiving end may use a bestreception beam for a specific transmission beam. Accordingly, thereceiving end may measure channel qualities regarding combinations of asingle transmission beam with all of the reception beams, and then, whena combination with a certain reception beam satisfies a condition, maydetermine that the specific transmission beam satisfies thepredetermined condition. That is, the ‘SBQI’ provides information on thetransmission beams.

When both the ‘best beam ID’ and the ‘SBQI’ are transmitted as shown intable 1, overhead is further required as much as at least one bit due tothe ‘SBQI.’ In order to prevent increasing overhead caused by ‘SBQI,’ areserved value of a field indicating the ‘best beam ID’ may be used. Forexample, when ‘best beam ID’ is 4-bit information, a value which doesnot indicate a beam ID may be used as shown in FIG. 5.

FIG. 5 illustrates a view showing an example of interpretation of uplinksignaling in a wireless communication system according to an exemplaryembodiment. FIG. 5 illustrates a case in which the ‘best beam ID’ isformed of 4 bits and 10 beams are used. Referring to FIG. 5, values‘0000’ to ‘1001’ which belong to a beam indication range 510 indicatebeams which are selected by the receiving end. That is, values ‘1011’ to‘1111’ from among the values expressed by 4 bits are not used toindicate beams. According to an exemplary embodiment of the presentdisclosure, values ‘1110’ and ‘1111’ which belong to an SBQI indicationrange 520 from among the values which do not indicate beams indicatesimilar information to the SBQI field of tables 1 and 2. For example,value ‘1110,’ which is ‘SBQI ON,’ indicates that the SBQI is set to apositive value, in other words, indicates that the channel qualities ofall of the beams are so good that communication is possible. Inaddition, value ‘1111,’ which is ‘SBQI OFF,’ indicates that the SBQI isset to a negative value, that is, indicates that the channel quality ofat least one beam is not so good that communication is possible. Herein,information indicating that communication is possible means that thechannel quality exceeds a pre-defined threshold value.

When signals can be transmitted to the receiving end with a beam otherthan the beam indicated by the best beam ID, the significance of theexistence of the best beam ID is reduced in comparison to the case inwhich the SBQI is set to a negative value. Accordingly, when thetransmitting end does not transmit signals with a specific analoguebeam, but transmits the SBQI indicating that communication is possible,the ‘best beam ID’ field may be omitted to reduce the overhead of theuplink signaling. For example, the uplink signaling related to thepreferred beam may be configured as shown in table 2 presented below:

TABLE 2 Number of Bits 1 Item SBQI (Similar Beam Quality Indicator)

As shown in table 2, the ‘best beam ID’ is excluded and only the ‘SBQI’is included. Although not expressed in table 2, the uplink signaling mayfurther include at least one of HARQ ACK/NACK, a PMI, an RI, and CQI.

In the above-described exemplary embodiment, the beam measurementinformation (for example, SBQI) indicates whether all of the beams havechannel qualities greater than or equal to a pre-defined threshold valueor any one of the beams does not have a channel quality greater than orequal to the pre-defined threshold value. However, according to anotherexemplary embodiment of the present disclosure, the beam measurementinformation may be configured to provide more detailed information. Forexample, the beam measurement information provides information on agroup basis. For example, when the transmitting end uses 16 transmissionbeams, four groups may be defined as shown in FIG. 6. FIG. 6 illustratesa view showing an example of classified beam groups in a wirelesscommunication system according to an exemplary embodiment of the presentdisclosure. Referring to FIG. 6, the transmitting end may use 16transmission beams, and four beams are grouped to a single group. Thatis, beams #1 to #4 are included in group 1 610, beams #5 to #8 areincluded in group 2 620, beams #9 to #12 are included in group 3 630,and beams #13 to #16 are included in group 4 640. In FIG. 6, physicallyadjacent beams are defined as one group. However, according to anotherexemplary embodiment of the present disclosure, beams which are notphysically adjacent may be defined as one group.

The above-described definition of the group may be shared by thetransmitting end and the receiving end. For example, the group may bepre-defined or may be forwarded through a broadcasting message of thetransmitting end or a network entry process. Accordingly, the receivingend may measure channel qualities regarding the beams using the beammeasurement reference signals, and transmit an index of a group in whichall of the beams have channel qualities greater than or equal to apre-defined threshold value as the beam measurement information. Inother words, an index of a group including beams which have similarchannel qualities may be forwarded as the beam measurement information.In this case, the uplink signaling may be configured as shown in table 3presented below:

TABLE 3 Number of Bits Variable 2 Items Best Beam ID SBQGI(Similar BeamQuality Group Indicator)

In table 3, the ‘best beam ID’ indicates a beam having a best channelquality. The ‘SBQGI,’ which is beam measurement information, indicates agroup including beams which have channel qualities greater than or equalto a threshold value. In the case of FIG. 3, the ‘SBQGI’ field is formedof 2 bits. The ‘SBQGI’ field of 2 bits is based on the premise that thenumber of beam groups is four or less. Accordingly, according to anotherexemplary embodiment of the present disclosure, when the number of beamgroups is 5 or more, the ‘SBQGI’ field may be formed of 3 or more bits.Although not expressed in table 3, the uplink signaling may furtherinclude at least one of HARQ ACK/NACK, a PMI, an RI, and CQI.

Similarly in the case of table 2, the ‘best beam ID’ field may beomitted to reduce the overhead of the uplink signaling. For example, theuplink signaling related to the preferred beam may be configured asshown in table 4:

TABLE 4 Number of Bits 1 Item SBQGI (Similar Beam Quality GroupIndicator)

As shown in table 4, the ‘best beam ID’ is excluded and only the SBQGI′is included. Although not expressed in table 4, the uplink signaling mayfurther include at least one of HARQ ACK/NACK, a PMI, an RI, and CQI.

According to another exemplary embodiment of the present disclosure, thebeam measurement information may be configured to provide more detailedinformation. For example, the beam measurement information may indicatewhether each of the beams has a channel quality greater than or equal toa threshold value or not. For example, when the transmitting end uses 16transmission beams, the beam measurement information may be configuredin the format of a bitmap as shown in FIG. 7.

FIG. 7 illustrates a view showing an example of a configuration of abitmap in a wireless communication system according to an exemplaryembodiment of the present disclosure. Referring to FIG. 7, the bitmap710 includes 16 bits b₀ to b₁₅, and the bits correspond to the 16 beamsof the transmitting end. The value of each of the bits indicates whetherthe channel quality of the corresponding beam is greater than or equalto a threshold value or not. For example, when b₂ corresponding to beam#3 is set to a positive value (for example, 1), the channel quality ofbeam #3 is greater than or equal to the threshold value. In this case,the transmitting end may allocate beam #3 to the receiving end.

The corresponding relationship between the bits in the bitmap and thebeams may be shared by the transmitting end and the receiving end. Forexample, the corresponding relationship may be pre-defined or may beforwarded through a broadcasting message of the transmitting end or anetwork entry process. Accordingly, the receiving end may measure achannel quality regarding each of the beams using the beam measurementreference signals, set the value of each of the bits in the bitmapaccording to whether each of the beams has a channel quality greaterthan or equal to a pre-defined threshold value, and transmit the bitmapas the beam measurement information. As such, detailed beam measurementinformation on each of the beams may be forwarded. In this case, theuplink signaling may be configured as shown in table 5 presented below:

TABLE 5 Number of Bits Variable 16 Items Best Beam ID SBQBI (SimilarBeam Quality Bitmap Indicator)

In table 5, the ‘best beam ID’ indicates a beam having a best channelquality. The ‘SBQBI’, which is beam measurement information, indicates agroup including beams which have channel qualities greater than or equalto a threshold value. In the case of table 5, the ‘SBQBI’ field isformed of 16 bits. According to another exemplary embodiment of thepresent disclosure, when the number of beams is different, the number ofbits of the ‘SBQBI’ field may be different. Although not expressed intable 5, the uplink signaling may further include at least one HARQACK/NACK, a PMI, an RI, and CQI.

Similarly in the case of table 2, the ‘best beam ID’ field may beomitted to reduce the overhead of the uplink signaling. For example, theuplink signaling related to the preferred beam may be configured asshown in table 6:

TABLE 6 Number of Bits 16 Item SBQBI (Similar Beam Quality BitmapIndicator)

As shown in table 6, the ‘best beam ID’ is excluded and only the SBQBI′is included. Although not expressed in table 6, the uplink signaling mayfurther include at least one of HARQ ACK/NACK, a PMI, an RI, and a CQI.

Hereinafter, the operation and configuration of the receiving end andthe transmitting end using the beam measurement information as describedabove will be explained.

FIG. 8 illustrates a view showing an operation procedure of a receivingend in a wireless communication system according to an exemplaryembodiment of the present disclosure.

Referring to FIG. 8, the receiving end measures channel qualities ofbeam combinations in step 801. That is, the transmitting end supports aplurality of transmission beams, and the receiving end supports at leastone reception beam. Accordingly, as many beam combinations as the numberof transmission beams and the number of reception beams may begenerated. The receiving end may receive reference signals which arebeamformed for transmission with transmission beams by beamforming withreception beams, and measure channel qualities. The channel quality mayinclude at least one of Received Signal Strength (RSS), a Signal toInterference and Noise Ratio (SINR), a Carrier to Interference and NoiseRatio (CINR), a Signal to Noise Ratio (SNR), and channel capacity.

After measuring the channel qualities, the receiving end proceeds tostep 803 to generate beam measurement information according statisticson the channel qualities. The beam measurement information ismeasurement information regarding a plurality of beams as well as a bestanalogue beam, and indicates whether all transmission beams, a group oftransmission beams, or an individual transmission beam is allowed to bearbitrarily allocated. For example, the beam measurement information maybe configured like the above-described SBQI, SBQGI, or SBQBI. Herein,the statistics on the channel qualities may include at least one ofinformation on whether channel qualities of all of the beams satisfy apredetermined criterion or not, similarity of the channel qualities ofall of the beams, information on whether channel qualities of all of thebeams of a group satisfy a predetermined criterion, similarity of thechannel qualities of all of the beams of the group, information onwhether a channel quality of each of the beams satisfies a predeterminedcriterion, and similarity of the channel qualities of the beamssatisfying the predetermined criterion. That is, the beam measurementinformation may indicate at least one of whether the channel qualityregarding all of the transmission beams, a group of transmission beams,or an individual transmission beam satisfies a predetermined criterionor not, and whether channel qualities are similar or not.

After generating the beam measurement information, the receiving endproceeds to step 805 to transmit the beam measurement information. Thebeam measurement information may have a format of a message. Accordingto another exemplary embodiment, the beam measurement information mayhave a format of a physical sequence or a codeword. In this case, inaddition to the beam measurement information, the receiving end mayfurther transmit at least one of information indicating a best analoguebeam, HARQ ACK/NACK, a PMI, an RI, and a CQI.

FIG. 9 illustrates a view showing an operation procedure of thereceiving end in the wireless communication system according to anotherexemplary embodiment of the present disclosure.

Referring to FIG. 9, the receiving end measures a channel quality foreach beam combination using reference signals for beam measurement whichare received from the transmitting end in step 901. The referencesignals may be received through OFDM symbols. Accordingly, the receivingend may receive the reference signals transmitted through the OFDMsymbols and measure as many times as the total number of analogue beamcombinations, and store the result of the measurement. Herein, the beamcombinations may refer to pairs of transmission beams and receptionbeams.

After measuring the channel quality for each of the beam combinationsusing the reference signals, the receiving end proceeds to step 903 todetermine a best analogue beam based on the measured channel quality. Inthis case, the receiving end may further determine a best precoder fordigital beamforming. That is, the receiving end may determine a beamcombination having the best channel quality by comparing the channelqualities of the beam combinations. Herein, the channel quality mayinclude received signal strength.

Next, the receiving end proceeds to step 905 to determine whether thechannel qualities of all of the beams satisfy a predetermined condition,that is, whether the channel qualities are greater than or equal to afirst threshold value or not. Herein, all of the beams refer totransmission beams. That is, the transmission beams and the receptionbeams have a one-to-many relationship, but, when the predeterminedcondition is satisfied in a combination with at least one receptionbeam, the receiving end determines that the corresponding transmissionbeams satisfy the predetermined condition. The first threshold value maybe defined differently according to various exemplary embodiments. Forexample, the first threshold value may be a threshold value of a channelquality (for example, received signal strength, an SINR, a CINR, an SNR,channel capacity, etc.) for guaranteeing a minimum service quality. Whenat least one of the channel qualities of all of the beams is less thanthe first threshold value, the receiving end proceeds to step 913.

On the other hand, when the channel qualities of all of the beams aregreater than or equal to the first threshold value, the receiving endproceeds to step 907 to calculate the similarity of the channelqualities of all of the beam combinations. For example, the receivingend calculates a variance of the channel qualities. For example, whenthe channel quality is received signal strength, the receiving end maycalculate statistics regarding how far the received signal strengths ofthe beam combinations are spread out.

After calculating the similarity, the receiving end proceeds to step 909to determine whether the similarity satisfies a predetermined conditionor not, in other words, whether the similarity is greater than or equalto a second threshold value. For example, when the similarity isevaluated based on a variance, and the variance is less than or equal toa specific threshold value, the similarity is determined to be greaterthan or equal to the second threshold value. Since a high varianceindicates that the channel qualities are very spread out, a smallvariance indicates that the channel qualities are similar.

When the similarity satisfies the predetermined condition, the receivingend proceeds to step 911 to set the SBQI to a positive value (forexample, 1). The SBQI, which is beam measurement information formed of 1bit, indicates whether a beam other than the beam having the bestchannel quality is allowed to be allocated or not. That is, thereceiving end sets the SBQI to a value indicating that all of the beamsare allowed to be allocated. According to another exemplary embodiment,the SBQI may be included in a field for forwarding other information.For example, when the SBQI is indicated through a field indicating abest analogue beam, the receiving end may set the field to a value whichis defined for the SBQI set to the positive value, in addition to avalue indicating a specific analogue beam.

On the other hand, when the similarity does not satisfy thepredetermined condition, the receiving end proceeds to step 913 to setthe SBQI to a negative value (for example, 0). That is, the receivingend sets the SBQI to a value indicating that a specific transmissionbeam should be allocated. According to another exemplary embodiment ofthe present disclosure, the SBQI may be included in a field forforwarding other information. For example, when the SBQI is indicatedthrough a field indicating a best analogue beam, the receiving end mayset the field to a value which is defined for the SBQI set to thenegative value, in addition to a value indicating a specific analoguebeam.

Thereafter, the receiving end proceeds to step 915 to transmit a signalincluding the SBQI. The signal including the SBQI may have a format of amessage, a physical sequence, or a codeword. In addition, the receivingend may further transmit at least one of information indicating a bestanalogue beam, HARQ ACK/NACK, a PMI, an RI, and a CQI, in addition tothe SBQI.

Thereafter, the receiving end proceeds to step 917 to receive beamformedsignals from the transmitting end. When the SBQI is set to a negativevalue, the receiving end may receive the beamformed signals using thebest analogue beam or the analogue beam which is determined by thetransmitting end (for example, a base station). When the SBQI is set toa positive value, the receiving end may receive the beamformed signalsusing the best analogue beam at the base station or the analogue beamwhich is determined by the transmitting end. In this case, the receivingend may perform beamforming for reception using the reception beamscorresponding to the transmission beams which are used for beamformingat the transmitting end.

FIG. 10 illustrates a view showing an operation procedure of thereceiving end in the wireless communication system according to anotherexemplary embodiment of the present disclosure.

Referring to FIG. 10, the receiving end measures a channel quality foreach beam combination using reference signals for beam measurement whichare received from the transmitting end in step 1001. The referencesignals may be received through OFDM symbols. Accordingly, the receivingend may receive the reference signals transmitted through the OFDMsymbols and measure as many times as the total number of analogue beamcombinations, and store the result of the measurement. Herein, the beamcombinations may refer to pairs of transmission beams and receptionbeams.

After measuring the channel quality for each of the beam combinationsusing the reference signals, the receiving end proceeds to step 1003 todetermine a best analogue beam based on the measured channel quality. Inthis case, the receiving end may further determine a best precoder fordigital beamforming. That is, the receiving end may determine a beamcombination having the best channel quality by comparing the channelqualities of the beam combinations. Herein, the channel quality mayinclude received signal strength.

Next, the receiving end proceeds to step 1005 to determine whether thechannel qualities of all of the beams satisfy a predetermined condition,that is, whether the channel qualities are greater than or equal to athreshold value or not. Herein, all of the beams refer to transmissionbeams. That is, the transmission beams and the reception beams have aone-to-many relationship, but, when the predetermined condition issatisfied in a combination with at least one reception beam, thereceiving end determines that the corresponding transmission beamssatisfy the predetermined condition. The threshold value may be defineddifferently according to various exemplary embodiments. For example, thethreshold value may be a threshold value of a channel quality (forexample, received signal strength, an SINR, a CINR, an SNR, channelcapacity, etc.) for guaranteeing a minimum service quality.

When the channel qualities of all of the beams are greater than or equalto the threshold value, the receiving end proceeds to step 1007 to setthe SBQI to a positive value (for example, 1). The SBQI, which is beammeasurement information formed of 1 bit, indicates whether a beam otherthan the beam having the best channel quality is allowed to be allocatedor not. That is, the receiving end sets the SBQI to a value indicatingthat all of the beams are allowed to be allocated. According to anotherexemplary embodiment, the SBQI may be included in a field for forwardingother information. For example, when the SBQI is indicated through afield indicating a best analogue beam, the receiving end may set thefield to a value which is defined for the SBQI set to the positivevalue, in addition to a value indicating a specific analogue beam.

On the other hand, when the channel quality of at least one beam is lessthan the threshold value, the receiving end proceeds to step 1009 to setthe SBQI to a negative value (for example, 0). That is, the receivingend sets the SBQI to a value indicating that a specific transmissionbeam should be allocated. According to another exemplary embodiment ofthe present disclosure, the SBQI may be included in a field forforwarding other information. For example, when the SBQI is indicatedthrough a field indicating a best analogue beam, the receiving end mayset the field to a value which is defined for the SBQI set to thenegative value, in addition to a value indicating a specific analoguebeam.

Thereafter, the receiving end proceeds to step 1011 to transmit a signalincluding the SBQI. The signal including the SBQI may have a format of amessage. According to another exemplary embodiment of the presentdisclosure, the message including the SBQI may have a format of aphysical sequence or a codeword. In this case, the receiving end mayfurther transmit information indicating the best analogue beam inaddition to the SBQI. The best analogue beam may be indicated by a beamID. Furthermore, the receiving end may further transmit at least one ofHARQ ACK/NACK, a PMI, an RI, and a CQI.

Thereafter, the receiving end proceeds to step 1013 to receivebeamformed signals from the transmitting end. When the SBQI is set to anegative value, the receiving end may receive the beamformed signalsusing the best analogue beam. When the SBQI is set to a positive value,the receiving end may receive the beamformed signals using the bestanalogue beam at the base station or the analogue beam which isdetermined by the transmitting end. In this case, the receiving end mayperform beamforming for reception using the reception beamscorresponding to the transmission beams which are used for beamformingat the transmitting end.

FIG. 11 illustrates a view showing an operation procedure of thereceiving end in the wireless communication system according to anotherexemplary embodiment of the present disclosure.

Referring to FIG. 11, the receiving end measures a channel quality foreach beam combination using reference signals for beam measurement whichare received from the transmitting end in step 1101. The referencesignals may be received through OFDM symbols. Accordingly, the receivingend may receive the reference signals transmitted through the OFDMsymbols and measure as many times as the total number of analogue beamcombinations, and store the result of the measurement. Herein, the beamcombinations may refer to pairs of transmission beams and receptionbeams.

After measuring the channel quality for each of the beam combinationsusing the reference signals, the receiving end proceeds to step 1103 toselect a best analogue beam based on the measured channel quality. Inthis case, the receiving end may further select a best precoder fordigital beamforming. That is, the receiving end may select a beamcombination having the best channel quality by comparing the channelqualities of the beam combinations. Herein, the channel quality mayinclude received signal strength.

Next, the receiving end proceeds to step 1105 to select an nth group.The groups are generated by classifying the transmission beams of thetransmitting end, and each of the groups includes a plurality oftransmission beams. The groups may be classified in different waysaccording to various exemplary embodiments of the present disclosure.The n is initialized to 1 at the start of the present procedure andsequentially increases. Accordingly, steps 1107 to 1117 may be repeatedwith respect to each of the groups.

Thereafter, the receiving end proceeds to step 1107 to determine whetherthe channel qualities of all of the beams included in the nth groupsatisfy a predetermined condition, that is, whether the channelqualities are greater than or equal to a first threshold value. Herein,all of the beams refer to transmission beams. That is, the transmissionbeams and the reception beams have a one-to-many relationship, but, whenthe predetermined condition is satisfied in a combination with at leastone reception beam, the receiving end determines that the correspondingtransmission beams satisfy the predetermined condition. The firstthreshold value may be defined differently according to variousexemplary embodiments. For example, the first threshold value may be athreshold value of a channel quality (for example, received signalstrength, an SINR, a CINR, an SNR, channel capacity, etc.) forguaranteeing a minimum service quality. When at least one of the channelqualities of all of the beams included in the nth group is less than thefirst threshold value, the receiving end proceeds to step 1115.

On the other hand, when the channel qualities of all of the beamsincluded in the nth group are greater than or equal to the firstthreshold value, the receiving end proceeds to step 1109 to calculatethe similarity of the channel qualities of all of the beam combinationsincluded in the nth group. For example, the receiving end calculates avariance of the channel qualities. For example, when the channel qualityis received signal strength, the receiving end may calculate statisticsregarding how far the received signal strengths of the beam combinationsare spread out.

After calculating the similarity, the receiving end proceeds to step1111 to determine whether the similarity satisfies a predeterminedcondition or not, in other words, whether the similarity is greater thanor equal to a second threshold value. For example, when the similarityis evaluated based on a variance, and the variance is less than or equalto a specific threshold value, the similarity is determined to begreater than or equal to the second threshold value. Since a highvariance indicates that the channel qualities are very spread out, asmall variance indicates that the channel qualities are similar.

When the similarity satisfies the predetermined condition, the receivingend proceeds to step 1113 to set a bit value of an SBQGI correspondingto the nth group to a positive value (for example, 1). The SBQGI, whichis beam measurement information formed on a group basis, indicateswhether a beam other than the beam having the best channel quality inthe corresponding group is allowed to be allocated or not. That is, thereceiving end sets the bit value to a value indicating that all of thebeams included in the corresponding group are allowed to be allocated.

On the other hand, when the similarity does not satisfy thepredetermined condition, the receiving end proceeds to step 1115 to setthe bit value of the SBQGI corresponding to the nth group to a negativevalue (for example, 0). That is, the receiving end sets the SBQGI to avalue indicating that the beams included in the corresponding group arenot allowed to be allocated arbitrarily.

Next, the receiving end proceeds to step 1117 to determine whether thesetting of the SBQGI is completed or not. In other words, the receivingend determines whether all of the bit values of the SBQGI are set. Thatis, the receiving end determines whether steps 1107 to 1115 areperformed with respect to all of the groups.

When the setting of the SBQGI is not completed, the receiving endproceeds to step 1119 to increase n by 1 and then returns to step 1105.Accordingly, steps 1107 to 1115 are repeated with respect to the nextgroups.

On the other hand, when the setting of the SBQGI is completed, thereceiving end proceeds to step 1121 to transmit a signal including theSBQGI. The signal including the SBQGI may have a format of a message.According to another exemplary embodiment of the present disclosure, themessage including the SBQGI may have a format of a physical sequence ora codeword. In this case, the receiving end may further transmitinformation indicating a best analogue beam in addition to the SBQGI.The best analogue beam may be indicated by a beam ID. Furthermore, thereceiving end may further transmit at least one of HARQ ACK/NACK, a PMI,an RI, and a CQI.

Thereafter, the receiving end proceeds to step 1123 to receivebeamformed signals from the transmitting end. When all of the bits ofthe SBQGI are set to a negative value, the receiving end may receive thebeamformed signals using the best analogue beam. When at least one bitof the SBQGI is set to a positive value, the receiving end may receivethe beamformed signals using the best analogue beam at the base stationor the analogue beam which is selected by the transmitting end in thegroup corresponding to the positive value. In this case, the receivingend may perform beamforming for reception using the reception beamscorresponding to the transmission beams which are used for beamformingat the transmitting end.

In the exemplary embodiment illustrated in FIG. 11, the receiving endsets the bit value corresponding to the corresponding group to apositive value when the receiving end satisfies a first condition inwhich the channel qualities are greater than or equal to the firstthreshold value and a second condition in which the similarity of thechannel qualities is greater than or equal to the second thresholdvalue.

However, according to another exemplary embodiment of the presentdisclosure, when one of the first condition and the second condition issatisfied, the bit value corresponding to the corresponding group may beset to a positive value. In this case, when the channel qualities of allof the beams included in the nth group are greater than or equal to thefirst threshold value in step 1107, the receiving end may proceed tostep 1113. In addition, when at least one of the channel qualities ofall of the beams included in the nth group is less than the firstthreshold value, the receiving end may proceed to step 1109.

In addition, according to another exemplary embodiment of the presentdisclosure, the bit value corresponding to the corresponding group maybe set according to only the first condition. In this case, when thechannel qualities of all of the beams included in the nth group aregreater than or equal to the first threshold value in step 1107, thereceiving end may proceed to step 1113. In addition, when at least oneof the channel qualities of all of the beams included in the nth groupis less than the first threshold value, the receiving end may proceed tostep 1115. That is, steps 1109 to 1111 may be omitted.

In addition, according to another exemplary embodiment of the presentdisclosure, the bit value corresponding to the corresponding group maybe set according to only the second condition. In this case, step 1107may be omitted.

FIG. 12 illustrates a view showing an operation procedure of thereceiving end in the wireless communication system according to anotherexemplary embodiment of the present disclosure.

Referring to FIG. 12, the receiving end measures a channel quality foreach beam combination using reference signals for beam measurement whichare received from the transmitting end in step 1201. The referencesignals may be received through OFDM symbols. Accordingly, the receivingend may receive the reference signals transmitted through the OFDMsymbols and measure as many times as the total number of analogue beamcombinations, and store the result of the measurement. Herein, the beamcombinations may refer to pairs of transmission beams and receptionbeams.

After measuring the channel quality for each of the beam combinationsusing the reference signals, the receiving end proceeds to step 1203 todetermine a best analogue beam based on the measured channel quality. Inthis case, the receiving end may further determine a best precoder fordigital beamforming. That is, the receiving end may determine a beamcombination having the best channel quality by comparing the channelqualities of the beam combinations. Herein, the channel quality mayinclude received signal strength.

Next, the receiving end proceeds to step 1205 to determine, from amongall of the beams, a set of beams in which channel qualities are greaterthan or equal to a first threshold value and simultaneously similarityof the channel qualities is greater than or equal to a second thresholdvalue. The first threshold value may be defined differently according tovarious exemplary embodiments. For example, the first threshold valuemay be a threshold value of a channel quality (for example, receivedsignal strength, an SINR, a CINR, an SNR, channel capacity, etc.) forguaranteeing a minimum service quality. In addition, the similarity maybe expressed using a variance of the channel qualities. When thesimilarity is evaluated based on the variance, and the variance is lessthan or equal to a specific threshold value, the similarity isdetermined to be greater than or equal to the second threshold value.

After determining the set of beams, the receiving end proceeds to step1207 to set a value of an SBQBI based on the set of beams. The SBQBI,which is individual beam measurement information for each of thetransmission beams, indicates whether each of the transmission beams isallowed to be allocated. That is, the receiving end may set bit valuescorresponding to the beams belonging to the set of beams to a positivevalue (for example, 1), and set the other bit values to a negative value(for example, 2).

Thereafter, the receiving end proceeds to step 1209 to transmit a signalincluding the SBQBI. The signal including the SBQBI may have a format ofa message. According to another exemplary embodiment of the presentdisclosure, the message including the SBQBI may have a format of aphysical sequence or a codeword. In this case, the receiving end mayfurther transmit information indicating a best analogue beam in additionto the SBQBI. The best analogue beam may be indicated by a beam ID.Furthermore, the receiving end may further transmit at least one of HARQACK/NACK, a PMI, an RI, and a CQI.

Thereafter, the receiving end proceeds to step 1211 to receivebeamformed signals from the transmitting end. When the SBQBI is set to anegative value, the receiving end may receive the beamformed signalsusing the best analogue beam. When the SBQBI is set to a positive value,the receiving end may receive the beamformed signals using the bestanalogue beam at the base station or the analogue beam which isdetermined by the transmitting end. In this case, the receiving end mayperform beamforming for reception using the reception beamscorresponding to the transmission beams which are used for beamformingat the transmitting end.

In the exemplary embodiment illustrated in FIG. 12, the receiving enddetermines a set of beams satisfying a first condition in which thechannel qualities are greater than or equal to the first threshold valueand a second condition in which the similarity of the channel qualitiesis greater than or equal to the second threshold value.

However, according to another exemplary embodiment of the presentdisclosure, when one of the first condition and the second condition issatisfied, the set of beams may be determined. In this case, in step1205, the receiving end may determine beams satisfying at least one ofthe first condition and the second condition as the set of beams to setthe SBQBI to a positive value.

In addition, according to another exemplary embodiment of the presentdisclosure, the set of beams may be determined according to only thefirst condition or the second condition. In this case, in step 1205, thereceiving end may determine beams satisfying the first condition as theset of beams to set the SBQBI to a positive value or determine beamssatisfying the second condition as the set of beams to set the SBQBI toa positive value.

FIG. 13 illustrates a view showing an operation procedure of atransmitting end according to an exemplary embodiment of the presentdisclosure.

Referring to FIG. 13, the transmitting end receives beam measurementinformation in step 1301. The beam measurement information ismeasurement information regarding a plurality of beams as well as a bestanalogue beam, and indicates whether all transmission beams, a group oftransmission beams, or an individual transmission beam is allowed to bearbitrarily allocated. For example, the beam measurement information maybe configured like the above-described SBQI, SBQGI, or SBQBI. That is,the beam measurement information may indicate whether a channel qualityof all of the transmission beams, a group of the transmission beams, oran individual transmission beam satisfies a predetermined criterion ornot, and whether the channel qualities are similar or not.

After receiving the beam measurement information, the transmitting endproceeds to step 1303 to allocate an analogue transmission beam for thereceiving end based on the beam measurement information. For example,when frequency and time resources are not scarce in a specific analoguebeam, the beam measurement information may not be used. That is, whenthe resources are not scarce, the transmitting end allocates bestanalogue beams of the receiving ends to the receiving ends. However,when frequency and time resources are scarce in a specific analoguebeam, some of the receiving ends which select the specific analogue beamas a best analogue beam may not be allocated the best analogue beam. Inthis case, the transmitting end allocates an analogue beam other thanthe best analogue beam to the entirety or part of the receiving endswhich are allowed to be arbitrarily allocated beams according to thebeam measurement information. Herein, the other analogue beams areselected from a certain allocable range indicated by the beammeasurement information.

FIG. 14 illustrates a view showing an operation procedure of thetransmitting end in the wireless communication system according toanother exemplary embodiment of the present disclosure. FIG. 14illustrates the operation procedure of the transmitting endcorresponding to the operation procedure of the receiving end shown inFIG. 9 or 10.

Referring to FIG. 14, the transmitting end receives signals including anSBQI from at least one receiving end in step 1401. The SBQI, which isbeam measurement information formed of 1 bit, indicates whether a beamother than a beam having a best channel quality is allowed to beallocated. In addition to the SBQI, at least one of informationindicating a best analogue beam, HARQ ACK/NACK, a PMI, an RI, and a CQImay further be received.

Next, the transmitting end proceeds to step 1403 to perform firstscheduling. For example, the transmitting end arranges the at least onereceiving end according to priority and then allocates analogue beam,time, and frequency resources to each receiving end. In this case, thefirst scheduling is not final scheduling but temporary scheduling, andthe result of the first scheduling may be changed in the subsequentsteps.

After performing the first scheduling, the transmitting end proceeds tostep 1405 to determine whether frequency and time resources to beallocated are scarce in a specific analogue beam or not. That is, thetransmitting end determines whether an amount of frequency and timeresources to be allocated as a result of the first scheduling exceeds anamount of allocable frequency and time resources in the specificanalogue beam.

When the frequency and time resources are not scarce, the transmittingend proceeds to step 1407 to allocate the analogue beam, time, andfrequency resources according to the result of the first scheduling.That is, the result of the first scheduling is determined as finalscheduling. Thereafter, the transmitting end proceeds to step 1415.

On the other hand, when the frequency and time resources are abundant,the transmitting end proceeds to step 1409 to determine the priority ofthe receiving ends which are allowed to be arbitrarily allocated beams.The receiving ends which are allowed to be arbitrarily allocated beamsrefer to at least one receiving end which has transmitted an SBQI set toa positive value (for example, 1). In this case, the priority may bedetermined only for receiving ends which have selected the specificanalogue beam having the scarce resources as a best analogue beam fromamong the receiving ends allowed to be arbitrarily allocated beams.Alternatively, the priority may be determined for all of the receivingends which are allowed to be arbitrarily allocated beams regardless ofthe best analogue beam.

Next, the transmitting end proceeds to step 1411 to allocate thefrequency and time resources of the specific analogue beam having thescarce resources according to the priority. As a result, some receivingends given low priority may not be allocated the resources of thespecific analogue beam, that is, the resources of the best analoguebeam. According to circumstances, none of the receiving ends which areallowed to be arbitrarily allocated beams may be allocated the resourcesof the specific analogue beam.

Next, the transmitting end proceeds to step 1413 to allocate thefrequency and time resources of an analogue beam other than the specificanalogue beam having the scarce resources to a receiving end which isnot allocated the resources of the specific analogue beam. In otherwords, the transmitting end allocates the resources of an analogue beamother than the best analogue beam to the receiving end which determinesthe specific analogue beam as the best analogue beam but is notallocated the resources of the specific beam analogue. That is, somereceiving ends may be allocated an analogue beam other than the bestanalogue beam.

Thereafter, the transmitting end proceeds to step 1415 to notify the atleast one receiving end of the result of the allocation of theresources, and transmit signals according to the result of theallocation of the resources. In this case, the transmitting end mayperform beamforming for transmission according to allocation of theanalogue beams included in the result of the allocation of theresources.

FIG. 15 illustrates a view showing an operation procedure of thetransmitting end in the wireless communication system according toanother exemplary embodiment of the present disclosure. FIG. 15illustrates the operation procedure of the transmitting endcorresponding to the operation procedure of the receiving end shown inFIG. 11.

Referring to FIG. 15, the transmitting end receives signals including anSBQGI from at least one receiving end in step 1501. The SBQGI, which isbeam measurement information formed on a group basis, indicates whethera beam other than a beam having a best channel quality that is includedin a corresponding group is allowed to be allocated. In addition to theSBQGI, at least one of information indicating a best analogue beam, HARQACK/NACK, a PMI, an RI, and a CQI may further be received.

Next, the transmitting end proceeds to step 1503 to perform firstscheduling. For example, the transmitting end arranges the at least onereceiving end according to priority and then allocates analogue beam,time, and frequency resources to each receiving end. In this case, thefirst scheduling is not final scheduling but temporary scheduling, andthe result of the first scheduling may be changed in the subsequentsteps.

After performing the first scheduling, the transmitting end proceeds tostep 1505 to determine whether frequency and time resources to beallocated are scarce in a specific analogue beam or not. That is, thetransmitting end determines whether an amount of frequency and timeresources to be allocated as a result of the first scheduling exceeds anamount of allocable frequency and time resources in the specificanalogue beam.

When the frequency and time resources are abundant, the transmitting endproceeds to step 1507 to allocate the analogue beam, time, and frequencyresources according to the result of the first scheduling. That is, theresult of the first scheduling is determined as final scheduling.Thereafter, the transmitting end proceeds to step 1515.

On the other hand, when the frequency and time resources are abundant,the transmitting end proceeds to step 1509 to determine the priority ofthe receiving ends which are allowed to be arbitrarily allocated beams.The receiving ends which are allowed to be arbitrarily allocated beamsrefer to at least one receiving end which has transmitted an SBQGI inwhich at least one bit is set to a positive value (for example, 1). Inthis case, the priority may be determined only for receiving ends whichhave selected the specific analogue beam having the scarce resources asa best analogue beam from among the receiving ends allowed to bearbitrarily allocated beams. Alternatively, the priority may bedetermined for all of the receiving ends which are allowed to bearbitrarily allocated beams regardless of the best analogue beam.

Next, the transmitting end proceeds to step 1511 to allocate thefrequency and time resources of the specific analogue beam having thescarce resources according to the priority. As a result, some receivingends given low priority may not be allocated the resources of thespecific analogue beam, that is, the resources of the best analoguebeam. According to circumstances, none of the receiving ends which areallowed to be arbitrarily allocated beams may be allocated the resourcesof the specific analogue beam.

Next, the transmitting end proceeds to step 1513 to allocate thefrequency and time resources of an analogue beam other than the specificanalogue beam having the scarce resources to a receiving end which isnot allocated the resources of the specific analogue beam. In otherwords, the transmitting end allocates the resources of an analogue beamother than the best analogue beam to the receiving end which determinesthe specific analogue beam as the best analogue beam, but is notallocated the resources of the specific beam analogue. In this case, theother analogue beam is one of the beams included in a groupcorresponding to the bit which is set to the positive value in the SBQGItransmitted from the corresponding receiving end. That is, thetransmitting end allocates the resources of the analogue beams in thegroup which is allowed to be arbitrarily allocated beams to thereceiving end which is not allocated the resources of the specificanalogue beam.

Thereafter, the transmitting end proceeds to step 1515 to notify the atleast one receiving end of the result of the allocation of theresources, and transmit signals according to the result of theallocation of the resources. In this case, the transmitting end mayperform beamforming for transmission according to allocation of theanalogue beams included in the result of the allocation of theresources.

FIG. 16 illustrates a view showing an operation procedure of thetransmitting end in the wireless communication system according toanother exemplary embodiment of the present disclosure. FIG. 16illustrates the operation procedure of the transmitting endcorresponding to the operation procedure of the receiving end shown inFIG. 12.

Referring to FIG. 16, the transmitting end receives signals including anSBQBI from at least one receiving end in step 1601. The SBQBI, which isindividual beam measurement information regarding each of thetransmission beams, indicates whether each of the transmission beams isallowed to be allocated. In addition to the SBQBI, at least one ofinformation indicating a best analogue beam, HARQ ACK/NACK, a PMI, anRI, and a CQI may further be received.

Next, the transmitting end proceeds to step 1603 to perform firstscheduling. For example, the transmitting end arranges the at least onereceiving end according to priority and then allocates analogue beam,time, and frequency resources to each receiving end. In this case, thefirst scheduling is not final scheduling but temporary scheduling, andthe result of the first scheduling may be changed in the subsequentsteps.

After performing the first scheduling, the transmitting end proceeds tostep 1605 to determine whether frequency and time resources to beallocated are scarce in a specific analogue beam or not. That is, thetransmitting end determines whether an amount of frequency and timeresources to be allocated as a result of the first scheduling exceeds anamount of allocable frequency and time resources in the specificanalogue beam.

When the frequency and time resources are not scarce, the transmittingend proceeds to step 1607 to allocate the analogue beam, time, andfrequency resources according to the result of the first scheduling.That is, the result of the first scheduling is determined as finalscheduling. Thereafter, the transmitting end proceeds to step 1615.

On the other hand, when the frequency and time resources are abundant,the transmitting end proceeds to step 1609 to determine the priority ofthe receiving ends which are allowed to be arbitrarily allocated beams.The receiving ends which are allowed to be arbitrarily allocated beamsrefer to at least one receiving end which has transmitted an SBQBI inwhich at least one bit is set to a positive value (for example, 1). Inthis case, the priority may be determined only for receiving ends whichhave selected the specific analogue beam having the scarce resources asa best analogue beam from among the receiving ends allowed to bearbitrarily allocated beams. Alternatively, the priority may bedetermined for all of the receiving ends which are allowed to bearbitrarily allocated beams regardless of the best analogue beam.

Next, the transmitting end proceeds to step 1611 to allocate thefrequency and time resources of the specific analogue beam having thescarce resources according to the priority. As a result, some receivingends given low priority may not be allocated the resources of thespecific analogue beam, that is, the resources of the best analoguebeam. According to circumstances, none of the receiving ends which areallowed to be arbitrarily allocated beams may be allocated the resourcesof the specific analogue beam.

Next, the transmitting end proceeds to step 1613 to allocate thefrequency and time resources of an analogue beam other than the specificanalogue beam having the scarce resources to a receiving end which isnot allocated the resources of the specific analogue beam. In otherwords, the transmitting end allocates the resources of an analogue beamother than the best analogue beam to the receiving end which determinesthe specific analogue beam as the best analogue beam, but is notallocated the resources of the specific beam analogue. In this case, theother analogue beam is one of at least one beam corresponding to the bitwhich is set to the positive value in the SBQBI transmitted from thecorresponding receiving end. That is, the transmitting end allocates theresources of an analogue beam which is allowed to be arbitrarilyallocated to the receiving end which is not allocated the resources ofthe specific analogue beam.

Thereafter, the transmitting end proceeds to step 1615 to notify the atleast one receiving end of the result of the allocation of theresources, and transmit signals according to the result of theallocation of the resources. In this case, the transmitting end mayperform beamforming for transmission according to allocation of theanalogue beams included in the result of the allocation of theresources.

FIG. 17 illustrates a view showing a configuration of a receiving end ina wireless communication system according to an exemplary embodiment ofthe present disclosure.

Referring to FIG. 17, the receiving end includes a Radio Frequency (RF)processor 1710, a baseband processor 1720, a storage 1730, and acontroller 1740.

The RF processor 1710 performs a function to transmit and receivesignals through a radio channel, such as converting a band of signals,amplifying, etc. That is, the RF processor 1710 up-converts basebandsignals provided from the baseband processor 1720 into RF band signals,and then transmits the signals through an antenna, and down-converts RFband signals received through the antenna into baseband signals. Forexample, the RF processor 1710 may include a transmission filter, areception filter 1712, an amplifier, a mixer, an oscillator, a Digitalto Analog Converter (DAC), an Analog to Digital Converter (ADC), etc. Asshown in FIG. 17, the receiving end may be provided with a plurality ofantennas, and the plurality of antennas may configure at least one arrayantenna. In addition, the RF processor 1710 may include a number of RFchains corresponding to the plurality of antennas. In addition, the RFprocessor 1710 may perform analog beamforming.

The baseband processor 1720 performs a conversion function between abaseband signal and a bit string according to a physical layer standardof the system. For example, when transmitting feedback information, thebaseband processor 1720 generates complex symbols by encoding andmodulating a transmission bit string. In addition, when receiving data,the baseband processor 1720 may restore a reception bit string bydemodulating and decoding the baseband signals provided from the RFprocessor 1710. For example, according to an OFDM method, whentransmitting feedback information, the bandband processor 1720 generatescomplex symbols by encoding and modulating the transmission bit string,maps the complex symbols onto subcarriers, and then configure OFDMsymbols by performing an Inverse Fast Fourier Transform (IFFT) operationand inserting a Cyclic Prefix (CP). In addition, when receiving data,the baseband processor 1720 divides the baseband signals provided fromthe RF processor 1710 on an OFDM symbol basis, restores the signalsmapped onto the subcarriers by performing an FFT operation, and thenrestores the reception bit string by demodulating and decoding. Inaddition, the baseband processor 1720 may perform digital beamforming.

The baseband processor 1720 and the RF processor 1710 may transmit andreceive signals as described above. Accordingly, the baseband processor1720 and the RF processor 1710 may be referred to as a transmitter, areceiver, or a transceiver.

The storage 1730 stores data such as basic programs, applicationprograms, setting data, etc. for the operations of the receiving end. Inaddition, the storage 1730 provides stored data in response to a requestof the controller 1740.

The controller 1740 controls the overall operation of the receiving end.For example, the controller 1740 transmits and receives signals throughthe baseband processor 1720 and the RF processor 1710. According to anexemplary embodiment of the present disclosure, the controller 1740includes a beam measurer 1742 to measure channel qualities of beamcombinations of transmission beams of the transmitting end and receptionbeams of the receiving end. According to an exemplary embodiment of thepresent disclosure, the controller 1740 may generate and transmit beammeasurement information indicating that it is possible to allocate theplurality of beams. For example, the controller 1740 may control thereceiving end to perform the procedures shown in FIGS. 8 to 12. Theoperations of the controller 1740 according to an exemplary embodimentof the present disclosure are as follows.

According to an exemplary embodiment, the controller 1740 measures thechannel qualities of the beam combinations. Specifically, the controller1740 receives reference signals which are beamformed for transmissionwith transmission beams by beamforming for reception with receptionbeams through the RF processor 1710 and the baseband processor 1720, andmeasures the channel qualities. In addition, the controller 1740generates the beam measurement information according to statistics onthe channel qualities. The beam measurement information is measurementinformation regarding a plurality of beams as well as a best analoguebeam, and indicates whether all of the transmission beams, a group ofthe transmission beams, or an individual transmission beam is allowed tobe arbitrarily allocated or not. In addition, the controller 1740transmits the beam measurement information through the RF processor 1710and the baseband processor 1720. The beam measurement information mayhave a format of a message.

According to an exemplary embodiment of the present disclosure, the beammeasurement information may indicate whether beams other than a beamhaving a best channel quality are allowed to be allocated or not. Inthis case, when a first condition in which the channel qualities of allof the beams are greater than or equal to a first threshold value, and asecond condition in which similarity between the channel qualities ofall of the beams is greater than or equal to a second threshold valueare all satisfied, the controller 1740 sets an SBQI to a positive value(for example, 1). According to another exemplary embodiment of thepresent disclosure, when only one of the first condition and the secondcondition is satisfied, the SBQI may be set to a positive value.According to another exemplary embodiment of the present disclosure,only one of the first condition and the second condition may be applied.

According to another exemplary embodiment of the present disclosure, thebeam measurement information may indicate whether beams other than thebeam having the best channel quality that are included in at least onegroup are allowed to be allocated. In this case, when a first conditionin which the channel qualities of all of the beams included in aspecific group are greater than or equal to a first threshold value, anda second condition in which similarity between the channel qualities ofall of the beams is greater than or equal to a second threshold valueare all satisfied, the controller 1740 sets a bit of an SBQGIcorresponding to the specific group to a positive value (for example,1). According to another exemplary embodiment of the present disclosure,when only one of the first condition and the second condition issatisfied, the corresponding bit of the SBQGI may be set to a positivevalue. According to another exemplary embodiment of the presentdisclosure, only one of the first condition and the second condition maybe applied.

According to another exemplary embodiment of the present disclosure, thebeam measurement information may indicate whether each of thetransmission beams is allowed to be allocated. In this case, thecontroller 1740 determines a set of beams satisfying a first conditionin which the channel qualities of all of the beams are greater than orequal to a first threshold value and a second condition in whichsimilarity between the channel qualities of all of the beams is greaterthan or equal to a second threshold value. In addition, the controller1740 sets bits corresponding to the beams of the set of beams in theSBQBI to a positive value (for example, 1). According to anotherexemplary embodiment of the present disclosure, when only one of thefirst condition and the second condition is satisfied, the set of beamsmay be determined. According to another exemplary embodiment of thepresent disclosure, only one of the first condition and the secondcondition may be applied.

FIG. 18 illustrates a view showing a block configuration of atransmitting end in a wireless communication system according to anexemplary embodiment of the present disclosure.

Referring to FIG. 18, the transmitting end includes an RF processor1810, a baseband processor 1820, a storage 1830, and a controller 1840.

The RF processor 1810 performs a function to transmit and receivesignals through a radio channel, such as converting a band of signals,amplifying, etc. That is, the RF processor 1810 up-converts basebandsignals provided from the baseband processor 1820 into RF band signals,and then transmits the signals through an antenna, and down-converts RFband signals received through the antenna into baseband signals. Forexample, the RF processor 1810 may include a transmission filter, areception filter 1812, an amplifier, a mixer, an oscillator, a DAC, anADC, etc. As shown in FIG. 18, the transmitting end may be provided witha plurality of antennas, and the plurality of antennas may configure atleast one array antenna. In addition, the RF processor 1810 may includea number of RF chains corresponding to the plurality of antennas. Inaddition, the RF processor 1810 may perform analog beamforming.

The baseband processor 1820 performs a conversion function between abaseband signal and a bit string according to a physical layer standardof the system. For example, when transmitting data, the basebandprocessor 1820 generates complex symbols by encoding and modulating atransmission bit string. In addition, when receiving feedbackinformation, the baseband processor 1820 may restore a reception bitstring by demodulating and decoding the baseband signals provided fromthe RF processor 1810. For example, according to an OFDM method, whentransmitting data, the baseband processor 1820 generates complex symbolsby encoding and modulating a transmission bit string, maps the complexsymbols onto subcarriers, and then configures OFDM symbols by performingan IFFT operation and inserting a CP. In addition, when receivingfeedback information, the baseband processor 1820 divides the basebandsignals provided from the RF processor 1810 on an OFDM symbol basis,restores the signals mapped onto the subcarriers by performing an FFToperation, and then restores a reception bit string by demodulating anddecoding. In addition, the baseband processor 1820 may perform digitalbeamforming.

The baseband processor 1820 and the RF processor 1810 may transmit andreceive signals as described above. Accordingly, the baseband processor1820 and the RF processor 1810 may be referred to as a transmitter, areceiver, or a transceiver.

The storage 1830 stores data such as basic programs, applicationprograms, setting data, etc. for the operations of the transmitting end.In addition, the storage 1830 provides stored data in response to arequest of the controller 1840.

The controller 1840 controls the overall operation of the transmittingend. For example, the controller 1840 transmits and receives signalsthrough the baseband processor 1820 and the RF processor 1810. Accordingto an exemplary embodiment of the present disclosure, the controller1840 includes a scheduler 1842 to allocate analogue beams based on beammeasurement information received from a receiving end. According to anexemplary embodiment of the present disclosure, the controller 1840 mayreceive the beam measurement information indicating that a plurality ofbeams are allocable and control to schedule based on the beammeasurement information. For example, the controller 1840 may controlthe transmitting end to perform the procedures shown in FIGS. 13 to 16.The operations of the controller 1840 according to an exemplaryembodiment of the present disclosure are as follows.

According to an exemplary embodiment of the present disclosure, thecontroller 1840 receives beam measurement information through the RFprocessor 1810 and the baseband processor 1820. The beam measurementinformation is measurement information regarding a plurality of beams aswell as a best analogue beam, and indicates whether all transmissionbeams, a group of the transmission beams, or an individual transmissionbeam is allowed to be arbitrarily allocated or not. In addition, thecontroller 1840 allocates an analogue transmission beam for thereceiving end based on the beam measurement information. For example,when frequency and time resources are scarce in a specific analoguebeam, the controller 1840 allocates an analogue beam other than the bestanalogue beam to the entirety or part of the receiving ends which areallowed to be arbitrarily allocated beams based on the beam measurementinformation. Herein, the other analogue beam is selected from anarbitrarily allocable range indicated by the beam measurementinformation.

According to an exemplary embodiment of the present disclosure, the beammeasurement information may indicate whether beams other than the beamhaving the best channel quality are allowed to be allocated or not. Inthis case, the controller 1840 may allocate frequency and time resourcesof an analogue beam other than a specific analogue beam having scarceresources to a receiving end which is not allocated the resources of thespecific analogue beam. Herein, the other analogue beam is one of all ofthe analogue beams other than the specific analogue beam.

According to another exemplary embodiment, the beam measurementinformation may indicate whether beams other than the beam having thebest channel quality that are included in at least one group are allowedto be allocated or not. In this case, the controller 1840 may allocatefrequency and time resources of an analogue beam other than a specificanalogue beam having scarce resources to a receiving end which is notallocated the resources of the specific analogue beam. Herein, the otheranalogue beam may be one of the beams included in a group correspondingto a bit which is set to a positive value in the beam measurementinformation transmitted by the corresponding receiving end.

According to another exemplary embodiment of the present disclosure, thebeam measurement information may indicate whether each of thetransmission beams is allowed to be allocated. In this case, thecontroller 1840 may allocate frequency and time resources of an analoguebeam other than a specific analogue beam having scarce resources to areceiving end which is not allocated the resources of the specificanalogue beam. Herein, the other analogue beam may be one of at leastone beam corresponding to a bit which is set to a positive value in thebeam measurement information transmitted by the corresponding receivingend.

As described above, the transmitting end may perform beamforming fortransmission. To achieve this, the transmitting end includes a digitalbeamforming means and an analogue beamforming means. An exemplaryembodiment of the digital beamforming means and the analogue beamformingmeans is as explained below with reference to FIG. 19. FIG. 19illustrates a view showing a block configuration for beamforming in awireless communication system according to an exemplary embodiment.

Referring to FIG. 19, a device for beamforming according to an exemplaryembodiment of the present disclosure includes a digital beamformingblock 1910, a chain block 1920, and an analogue beamforming block 1930.Specifically, the digital beamforming block 1910 includes a MultipleInput Multiple Output (MIMO) encoder 1912 and a baseband precoder 1914.The chain block 1920 includes N chains, and each of the chains includesan IFFT block 1922, a Parallel to Serial (P/S) block 1924, and a DAC1926. The analogue beamforming block 1930 includes N mixers 1932-1 to1932-N, N RF beamformers 1934-1 to 1934-N which include a plurality ofphase and size conversion elements, N amplifiers 1936-1 to 1936-N whichinclude a plurality of Power Amplifiers (APs), and N array antennas1938-1 to 1938-N which include a plurality of antenna elements. Thestructure for beamforming shown in FIG. 19 is merely an example, and maybe implemented in various ways.

That is, the RF processor 1810 may include a configuration such as theanalogue beamforming block 1930 to perform the analogue beamforming. Inaddition, the baseband processor 1820 may include a configuration suchas the digital beamforming block 1910 to perform the digitalbeamforming.

The antenna arrays 1938-1 to 1938-N may form analogue beams in alldirections within a service coverage, and the directions of the analoguebeams may be determined in advance. The receiving end and thetransmitting end may have a similar beamforming structure. However, thenumber of antenna elements configuring the array antennas between thereceiving end and the transmitting end may be different. According tothe beamforming structure shown in FIG. 19, each of the transmitting endand the receiving end includes the plurality of array antennas 1938-1 to1938-N and forms analogue beams in each of the array antennas, and thusanalogue beams may be selected in each array antenna. In addition, sincethe plurality of array antennas 1938-1 to 1938-N are used, digitalprocoding may be performed in a baseband. In the case of FIG. 19, sinceN array antennas 1938-1 to 1938-N are configured, a precoding vectorpreferred in a digital codebook may be applied.

Methods based on the embodiments disclosed in the claims orspecification of the present disclosure may be implemented in hardware,software, or a combination of hardware and software.

When implemented in software, a computer readable recording medium forstoring one or more programs (software modules) may be provided. The oneor more programs stored in the computer readable recording medium areconfigured for execution performed by one or more processors in anelectronic device. The one or more programs include instructions forallowing the electronic device to execute the methods based on theembodiments disclosed in the claims or specification of the presentinvention.

The program (software module or software) may be stored in a randomaccess memory, a non-volatile memory including a flash memory, a ReadOnly Memory (ROM), an Electrically Erasable Programmable Read OnlyMemory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM(CD-ROM), Digital Versatile Discs (DVDs) or other forms of opticalstorage devices, and a magnetic cassette. Alternatively, the program maybe stored in a memory configured in combination of all or some of thesestorage media. In addition, the configured memory may be plural innumber.

Further, the program may be stored in an attachable storage devicecapable of accessing the electronic device through a communicationnetwork such as the Internet, an Intranet, a Local Area Network (LAN), aWide LAN (WLAN), or a Storage Area Network (SAN) or a communicationnetwork configured by combining the networks. The storage device mayaccess via an external port to the apparatus performing the exemplaryembodiments of the present disclosure. In addition, a separate storagedevice on the communication network may access the apparatus performingthe exemplary embodiments of the present disclosure.

In the exemplary embodiments of the present disclosure described above,the elements included in the present disclosure are expressed in asingular form or a plural form according to an exemplary embodiment.However, the singular form or plural form is just selected to suit to asuggested situation for the sake of easy explanation, and the presentdisclosure is not limited to the single or plural elements. Even when anelement is expressed in a plural form, the element may be provided as asingle element, and, even when an element is expressed in a singularform, the element may be provided as a plurality of elements.

While the invention has been shown and described with reference tocertain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. Therefore, the scope of the invention isdefined not by the detailed description of the invention but by theappended claims, and all differences within the scope will be construedas being included in the present invention.

What is claimed is:
 1. A method performed by a terminal, the methodcomprising: receiving, from a base station, a broadcast message forindicating a plurality of groups, wherein one of the plurality of groupsis associated with one or more transmission beams; receiving, from thebase station, downlink signals of transmission beams; and transmitting,to the base station, feedback information for indicating a beam groupamong the plurality of groups based on measurements of the downlinksignals, wherein each beam in the beam group corresponds to a sametime-frequency resource, wherein a channel quality for one or moretransmission beams corresponding to the beam group is greater than athreshold for selecting a transmission beam of the beam group, andwherein the channel quality comprises a received signal strength.
 2. Themethod of claim 1, wherein the broadcast message is received based on anetwork access procedure.
 3. The method of claim 1, wherein the feedbackinformation indicates the transmission beam of the beam group based on aphysical sequence of the feedback information.
 4. A method performed bya base station, the method comprising: transmitting a broadcast messagefor indicating a plurality of groups, wherein one of the plurality ofgroups is associated with one or more transmission beams; transmittingdownlink signals of transmission beams; and receiving, from a terminal,feedback information for indicating a beam group among the plurality ofgroups based on measurements of the downlink signals, wherein each beamin the beam group corresponds to a same time-frequency resource, whereina channel quality for one or more transmission beams corresponding tothe beam group is greater than a threshold for selecting a transmissionbeam of the beam group, and wherein the channel quality comprises areceived signal strength.
 5. The method of claim 4, wherein thebroadcast message is transmitted based on a network access procedure. 6.The method of claim 4, wherein the feedback information indicates thetransmission beam of the beam group based on a physical sequence of thefeedback information.
 7. A terminal, comprising: at least onetransceiver; and at least one processor coupled to the at least onetransceiver and configured to: receive, from a base station, a broadcastmessage for indicating a plurality of groups, wherein one of theplurality of groups is associated with one or more transmission beams,receive, from the base station, downlink signals of transmission beams,and transmit, to the base station, feedback information for indicating abeam group among the plurality of groups based on measurements of thedownlink signals, wherein each beam in the beam group corresponds to asame time-frequency resource, wherein a channel quality for one or moretransmission beams corresponding to the beam group is greater than athreshold for selecting a transmission beam of the beam group, andwherein the channel quality comprises a received signal strength.
 8. Theterminal of claim 7, wherein the broadcast message is received based ona network access procedure.
 9. The terminal of claim 7, wherein thefeedback information indicates the transmission beam of the beam groupbased on a physical sequence of the feedback information.
 10. A basestation, comprising: at least one transceiver; and at least oneprocessor coupled to the at least one transceiver and configured to:transmit a broadcast message for indicating a plurality of groups,wherein one of the plurality of groups is associated with one or moretransmission beams, transmit downlink signals of transmission beams, andreceive, from a terminal, feedback information for indicating a beamgroup among the plurality of groups based on measurements of thedownlink signals, wherein each beam in the beam group corresponds to asame time-frequency resource, wherein a channel quality for one or moretransmission beams corresponding to the beam group is greater than athreshold for selecting a transmission beam of the beam group, andwherein the channel quality comprises a received signal strength. 11.The base station of claim 10, wherein the broadcast message istransmitted based on a network access procedure.
 12. The base station ofclaim 10, wherein the feedback information indicates the transmissionbeam of the beam group based on a physical sequence of the feedbackinformation.